You've probably noticed that most hula performances are done in traditional Hawaiian clothing. Most people, myself included, usually think of grass skirts and coconut bras when they think of traditional Hawaiian garments, but there's a lot more to it than what we see as tourists!
Traditional Hawaiian clothing is made of tapa cloth, which is made out of bark and is typical of Polynesian culture.
In ancient Hawaiian culture, traditional female dancers wore a wrapped skirt, called a pāʻū, and were usually topless. Affluent Hawaiians wore long pāʻū that actually made their waists look wider and accentuated the dances the performed.
Traditional male dancers wore a loincloth, or the malo. Again, they might wear bulky malo made of many yards of tapa.
Dancers also wore decorations such as necklaces, bracelets, and anklets, as well as many lei (in the form of headpieces (leipo'o), necklaces, bracelets, and anklets (kupe'e)), and other accessories.
The materials for the lei worn in performance were gathered in the forest, after prayers to the mythological heroin Laka and the forest gods had been chanted.
The lei and tapa worn for sacred hula were considered imbued with the sacredness of the dance, and were not to be worn after the performance. Lei were typically left on the small altar to Laka found in every hālau, as offerings.

@fallingwater if I understand correctly, it not only accentuates the hips and the dances but it is also just a show of that person's wealth i.e. the more cloth or fabric you are able to wear/afford, the richer and more affluent member of society you are